SQL/MX 3.2 Management Manual (H06.25+, J06.14+)

RECOVER FILES $VOL.*.*, FROMARCHIVE
2. Check that dependent objects residing on other volumes have also been recovered and
re-create objects as necessary.
3. Verify the database by using the mxtool VERIFY utility. For more information, see the SQL/MX
Reference Manual.
4. Make new TMF online dumps of SQL/MX objects that reside on the volume. If the entire object
was re-created, take dumps of the entire object even if one or more partitions reside on different
volumes.
INITIALIZE DISK
The INITIALIZE DISK command prepares the disk for use on the system. This command deletes any
existing files on the volume, deletes the log of spared sectors, initializes the customer engineer
sector and the spare-tracks table, and optionally labels the disk. To recover an initialized disk
volume, follow the steps in “ALTER DISK, LABEL” (page 261).
START DISK and STOP DISK
Use the STOP DISK command on a mirrored volume pair to make one half of the pair inactive.
The active disk drive of the mirrored pair continues to maintain the current database, without the
protection of mirroring.
After the disk drive is stopped, you can bring the disk up as a phantom drive (without a name),
label the disk with another volume name, or reuse the disk in any other way. This operation is
often done on nodes where nonmirrored disk space is needed for a short time.
Later, you can return the previously stopped disk drive to its original mirrored state by performing
a START DISK.
You should not use the stopped drive to store production SQL/MX database files. You typically
use the drive for a test database or for temporary space for sort files. You must ensure that you
can make the volume inactive and revive the drive back to its original mirrored configuration with
no effect on the original database.
Use the STOP DISK command on a volume to put a particular volume out of operation. You can
later use the START DISK command to put the same disk back into operation. Inconsistency is
unlikely if the disk brought up is identical to the disk brought down. Always perform a STOPOPENS
DISK on the volume and a CONTROL DISK, REFRESH on the volume to ensure valid file labels
before you make the volume inactive.
CAUTION: You cannot use STOP DISK on a volume and replace the volume with an earlier
version of that same volume without causing inconsistencies in the database.
The only exception to the preceding rule is if the entire database has been consistently brought
down as a unit. For example, suppose that you use STOP DISK to bring down all the backup
volumes of the mirrored pairs containing SQL/MX objects in a consistent state. The other mirrored
set continues the active database, but the inactive mirrors also contain a set of consistent SQL/MX
objects.
You can also use STOP DISK to bring down the active database and START DISK to bring up the
saved database in a database swapping technique. This technique might be useful for testing
scenarios. As long as you bring each set of mirrors down and then up together, each copy of the
database continues to be consistent.
262 Performing Recovery Operations